mail - send or receive mail among users
mail person ...
mail [ -r ] [ -q ] [ -p ] [ -f file ]
Mail with no argument prints a user's mail, message-by-message, in last-in, first-out
order; the optional argument -r causes first-in, first-out order. If the -p flag is
given, the mail is printed with no questions asked; otherwise, for each message, mail
reads a line from the standard input to direct disposition of the message.
Go on to next message.
d Delete message and go on to the next.
p Print message again.
- Go back to previous message.
s [ file ] ...
Save the message in the named files (`mbox' default).
w [ file ] ...
Save the message, without a header, in the named files (`mbox' default).
m [ person ] ...
Mail the message to the named persons (yourself is default).
Put unexamined mail back in the mailbox and stop.
q Same as EOT.
x Exit, without changing the mailbox file.
Escape to the Shell to do command.
? Print a command summary.
An interrupt stops the printing of the current letter. The optional argument -q causes
mail to exit after interrupts without changing the mailbox.
When persons are named, mail takes the standard input up to an end-of-file (or a line with
just `.') and adds it to each person's `mail' file. The message is preceded by the
sender's name and a postmark. Lines that look like postmarks are prepended with `>'. A
person is usually a user name recognized by login(1). To denote a recipient on a remote
system, prefix person by the system name and exclamation mark (see uucp(1)).
The -f option causes the named file, e.g. `mbox', to be printed as if it were the mail
Each user owns his own mailbox, which is by default generally readable but not writable.
The command does not delete an empty mailbox nor change its mode, so a user may make it
unreadable if desired.
When a user logs in he is informed of the presence of mail.
/etc/passwd to identify sender and locate persons
mbox saved mail
/tmp/ma* temp file
dead.letter unmailable text
xsend(1), write(1), uucp(1)
There is a locking mechanism intended to prevent two senders from accessing the same mail-
box, but it is not perfect and races are possible.